Field
The present disclosure relates generally to energy storage devices, and more particularly to battery technology and the like.
Background
Owing in part to their relatively high energy densities, relatively high specific energy, light weight, and potential for long lifetimes, advanced rechargeable batteries are desirable for a wide range of consumer electronics, electric vehicle, grid storage and other important applications.
However, despite the increasing commercial prevalence of batteries, further development of these batteries is needed, particularly for potential applications in low- or zero-emission, hybrid-electrical or fully-electrical vehicles, consumer electronics, energy-efficient cargo ships and locomotives, aerospace applications, and power grids. In particular, further improvements are desired for various rechargeable batteries, such as rechargeable metal and metal-ion batteries (such as rechargeable Li and Li-ion batteries, rechargeable Na and Na-ion batteries, rechargeable Mg and Mg-ion batteries, etc.), rechargeable alkaline batteries, rechargeable metal hydride batteries, and lead acid batteries, to name a few.
In many different types of rechargeable batteries, active (charge storing) materials may be produced as high surface area porous structures or porous composites, where pores are exposed to electrolyte during battery operation. In some cases, formation of these pores may be desired in order to accommodate volume changes during battery operation or in order to reduce ion diffusion distances or electron diffusion distances. Examples of materials that exhibit volume changes include so-called conversion-type and so-called alloying-type electrode materials. In the case of metal-ion batteries (such as Li-ion batteries), examples of such conversion-type electrode materials include, but are not limited to, metal fluorides (such as lithium fluoride, iron fluoride, cupper fluoride, bismuth fluorides, etc.), metal chlorides, metal iodides, metal chalcogenides (such as sulfides), sulfur, oxides, metal nitrides, metal phosphides, metal hydrides, and others. In the case of metal-ion batteries (such as Li-ion batteries), examples of such alloying-type electrode materials include, but are not limited to, silicon, germanium, antimony, aluminum, magnesium, zinc, gallium, arsenic, phosphorous, silver, gold, cadmium, indium, tin, lead, bismuth, their alloys, and others. These materials often offer higher gravimetric and volumetric capacity than so-called intercalation electrodes used in commercial Li-ion batteries. Conversion-type electrodes are also commonly used in various aqueous batteries, such as alkaline batteries, metal hydride batteries, lead acid batteries, etc. These include, but are not limited to, various metals (such as iron, zinc, cadmium, lead, indium, etc.), metal oxides, metal hydroxides, metal oxyhydroxides, metal hydrides, to name a few.
In some cases, active materials that exhibit minimal volume changes during battery operation (for example, so-called intercalation materials, which are used in Li-ion batteries, such as lithium titanate or titanium oxide anode materials or lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium cobalt aluminum oxide, lithium manganese oxide and various other layered, spinel, olivine and tavorite-structured and other Li intercalation compounds, to name a few) may also be produced as porous particles or porous composite particles (e.g., as composites comprising these active materials and conductive carbon or another material) in order to improve their rate performance in batteries.
While high specific surface area or porosity in the active material particles may be advantageous for improving some of the performance characteristics of electrodes comprising such particles (for example, improving stability or increasing rate performance), it may also significantly enhance the degree of undesirable reactions with the electrolyte. Such undesirable reactions may include, for example, active material dissolution; electrolyte decomposition with the formation of, for example, undesirable gaseous, solid, or liquid products; so-called ion shuttle; and the irreversible loss of active ions (such as the loss of Li in the case of Li-ion batteries), to name a few. These undesirable reactions may lead to self-discharge, an increase in cell resistance, a reduction in accessible power, reduction in accessible energy, or the gradual loss of capacity. The high surface area of active materials may also significantly increase safety hazards associated with these batteries.
Accordingly, there remains a need for improved batteries, components, and other related materials and manufacturing processes.